split 8x57 necks

[sigshepardo]

I was shooting some Winchester 170 grain soft points today through my 1943 Mauser Kar98k. 2 of the 20 shots I fired had a quarter inch split from the bottom of the shoulder all the way up and almost the entire length of the neck. I plan on reloading 8mm, but If this keeps happening, I wont be able to afford it. Why are my necks splitting? These were factory ammo through a clean bore. Was it my rifle or the ammunition? Also on a side note, I had seen splits like this before in some old Yugo surplus steel case.

 

[Mike Irwin]

That sounds like bad annealing from the factory.

Not unknown.

 

[aktinker]

another source of 8mm brass...

...annealing, sizing, and cutting down .30-06 brass, there's a 1001 articles about it across several forums so I won't bother with the details. I load for my k98 too, but i couldn't convince myself to buy loaded ammo at a premium when I could not just load the ammo, but 'make' the brass myself. There's the issue of confusing your head stamps, but any responsible loader knows to keep their stuff in properly labels containers (and to keep those containers segregated). Just my 2 cents.

 

[Ideal Tool]

How do the unfired bullets fit in a fired case mouth? or can you measure the I.D. with calipers? Wonder if that war-time Mauser might have oversized chamber?

 

[David Wile]

Hey Rhett,

If I read your post correctly, it would seem you said your ammo that was splitting was brand new Winchester brand factory ammo. Like Mike said, it could be bad heat treating by the factory, but I never came across anything like that from Winchester ammo.

If you have had this rifle for many years and never had a problem like this before, then I would suspect the case quality as Mike suggested. However, if this rifle is new to you, and if these cartridges were the first you fired in it, I would be concerned about the chamber and the headspacing of same. If there is a problem with the rifle, splitting new cases can be a warning sign of a potential danger waiting ahead.

If the rifle is new to your use, a trip to a competent gunsmith to inspect the rifle and cases may be a good idea.

Keep me in mind when you first smell the new mown hay this spring.

Best wishes,
Dave Wile

 

[F. Guffey]

I do not know, but, what I do know is: Had you stopped shooting at the first sign of a problem you could have called Winchester with the problem and a lot #. But, still, there is a chance, your cases are once fired, once fired cases behave in a predictable manner as in a new/unfired/minimum length case is as good as it gets then comes once fired. You have 18 once fired cases, if I had 18 once fired cases that were suspect I would use my 338/06 or 35 Whelen versatile full length sizer die to neck-up the suspect cases, if after necking the 8mm cases up to 338/06 or 35 Whelen (neck dimensions) I found splits in the necks, I would conclude the cases were brittle.

When forming: I have formed 280 Remington to 35 Whelen, 30/06, 30 Gibbs and 338/06 without splits, EXCEPT for nickel cases, the price of forming shiny cases is close to 40% failure.

Then there is the crush test.

F. Guffey